The present invention relates to computer capture of object motion. More specifically, embodiments of the present invention relate to capturing of facial movement or performance of a actor.
Traditional computer animation of objects is determined by users known as animators. These animators are skilled artists who would specify movement of objects, such as people, within a computer environment. As a model for human movement, many animators often referred to how they moved, through the use of mirrors, video cameras, or the like.
animation has also been based more directly upon physical movement of actors. This animation is known in the film industry as motion-capture or performance capture. In such cases, an actor is equipped with a suit with a number of markers, and as the actor moves, a number cameras track the positions of the markers in space.
One of the pioneering companies in the field of motion-capture or performance-capture for animated feature films has been ImageMovers. ImageMovers, now ImageMovers Digital (IMD), has been the producer of animated features such as “Polar Express” (2004), “Monster House” (2006), and “Beowulf” (2007), and has been nominated for multiple Academy Awards®.
With current motion-capture systems, such as those provided by Vicon, the number of markers on the body of an actor may approach 200, and the number of markers on a face of an actor may approach 200. Additionally, a hundred cameras are provided that surround the set, so that as the actor moves on the set, the positions of the markers can roughly be determined.
The inventor has recognized that a drawback with current systems is that facial performance of an actor is often difficult to capture. The inventor attributes this to the small movement of facial markers of an actor compared to the larger movement of body markers of the actor. Because the distance between the actor and the cameras around the set is large compared to the movement of an eyebrow of an actor, for example, it is often difficult to resolve such movement, even when using a high resolution camera.
One system that attempts to address this issue has included the use of a rig that an actor wears that includes a camera to capture the right side of an actor's face, and another camera to capture the right side of an actor's face. Drawbacks to such systems include that the cameras use are heavy, and that the rigging worn by the actor are often heavy. Accordingly, actors often do not like to wear such rigs, or flatly refuse to wear such rigs.
One solution to this has been developed by ImageMovers Digital, the assignee of the present invention, and is described in the co-pending application described above. This solution provides a light-weight rig camera configuration that can capture multiple views of an actor's face without inhibiting their performance.
Another drawback to current systems includes that captured facial performance data are used for producing statistical models of facial animation. That statistical model then drives the animation. Because the model is statistical, nuances in actor facial movements, such as an actor's well-known facial quirks, grins, poses, or the like, are often not reflected in such statistical models. Because of this, the produced animation often lacks the “life” or “realism” needed to fully convey the actor's performance. Accordingly, computer animated characters based upon statistical techniques often fall within the “uncanny valley.”
In light of the above, what is initially desired are improved methods and apparatus addressing the problems described above.